Mat for lining beams in mine constructions

ABSTRACT

The disclosure relates to a wire mesh mat intended for the lining of supporting beams in mine roadways and tunnel constructions, and consisting of mat sections each having longitudinal and transverse rods welded together at their intersection points, the longitudinal rods having hooks at their ends, while the longitudinal rods are assembled together in pairs and have transverse rods at both ends of the mat section, whose welded joints are subject to shearing stress, but the spacing distances at opposite ends being different so that the mat sections can be successively interengaged with each other.

United States Patent [72] inventor Hans Reiter [56] References Citedgwlomstrasse 23, 4354 Damn, UNITED STATES PATENTS ermany pp No- 819661 ll\Yergsenbom 245/10 Ffled APTI281969 2,315,180 3/1943 onh 245/9 PatentedJuly B 197 i Art ur 94/13 32 Priority May 7, 1963 FOREIGN PATENTS 33]Germany 559,542 2/ 1944 Great Britain 245/8 [3 l 1 P 17 58 284': PrimaryExaminer-Richard .l. Herbst Attorney--Malcolm W. Fraser ABSTRACT: Thedisclosure relates to a wire mesh mat intended for the lining ofsupporting beams in mine roadways and tunnel constructions, andconsisting of mat sections each MAT FOR LININGSBEAMS IN MINE havinglongitudinal and transverse rods welded together at CON STRUCTIO N theirintersection points, the longitudinal rods having hooks at 2 Chums, 8Drawmg their ends, while the longitudinal rods are assembled together[52] 0.8. CI 245/9, in pairs and have transverse rods at both ends ofthe mat sec- 94/13 tion, whos e welded joints are subject to shearingstress, but the [51] Int. Cl Efllc 5/16 spacing distances at oppositeends being different so that the [50] Field 0! Search 245/8, 9, matsections can be successively interengaged with each other.

MAT FOR LINING BEAMS IN MINE CONSTRUCTIONS BACKGROUND OF THE INVENTIONIn such wire mesh mats the longitudinal rods are under severe tensilestress and are dimensioned accordingly. On the other hand the transverserods serve essentially for holding the mat together and accordingly areusually designed of lighter construction. The ends of the longitudinalrods must therefore be so designed that they can withstand the forces upto the limit of their parting strength, in order that there shall be anoptimum utilization of the material of which they are made. On the otherhand, however, these forces must be capable of being transmitted from anadjacent mat, as well as from a support beam itself, to the longitudinalrods.

It is already known, in a mat of the above-mentioned construction, tolocate the joint between the ends of the mats adjacent to the supportbeam. For this purpose the longitudinal rods assembled together in pairsare provided with obtuse angled bends, and at one end of the mat, wherethe ends of the longitudinal rods are spaced apart at a greater distancethan at the other end of the mat, they are provided with hooks havingsubstantially rectangular jaw apertures. Such mats are capable of beingprovided with additional protection at the forward end of the roadway,and satisfactory suspension of such mats can be ensured, while underload they exhibit a certain yieldability because, at the ends of thesemats where the longitudinal rods are spaced farther apart than at theother ends the transverse rods first of all approach each other beforethey are stressed under tension. However, there is a disadvantage that,in consequence of the special joint construction which is adopted, thehooks are placed only at one end of the mats and therefore theengagement at both sides of the two support beams which are bridged overby the mat, is not possible, and as a consequence the advantageous firmconnection between the mats and the beams is essentially lacking.

It is also already known, in wire mesh mats having longitudinal rodsassembled in pairs, to provide both ends with hooks, said hooks at oneend of the mat having a substantially rectangular jaw, and the oppositeend of the mats having hooks with an acute angled jaw for the purpose ofat least partial engagement of the support beam. However, such mats maynot be suspended within each other, and also cannot be provided withadditional protective means at the forward end of the roadway. They are,however, particularly safe against disturbance. For this purpose thelowest parts of the openings formed by the two hook jaws are at agreater spacing distance from each other than the distance between theouter edges of the two support beams, which are to be bridged over bythe mat. By reason of the clearance thus provided the mat can be pushedback in order that the acute angled jaw can be brought into engagementwith the support beam.

Finally, it has also already been proposed to weld at the ends of thelongitudinal rods punched metal plate members of hook form. In this way,practically any desired degree of high shearing strength can be achievedin the hooks and accordingly sufficiently high tensile strengths can beachieved in the longitudinal rods. However, the manufacture of such matsis comparatively difficult.

SUMMARY OF THE INVENTION The present invention takes as its basicpurpose the provision of a mat which permits progressive interengagementof a plurality of mat sections and at the same time affords thepossibility of providing security at the forward end of the roadway, theconstruction also having bent ends of the longitudinal rods to achievethe advantageous secure connection between the mat and the support beamswhich are to be bridged over, and achieving at the same time a tensilestrength of the mat connections which can if necessary be as large asthe tearing strength of the longitudinal rods.

This is achieved in accordance with the invention in that, at one end ofeach mat section the hooks are designed in known manner with asubstantially rectangular-shaped jaw and are provided at the oppositeends with hooks having an acute angled jaw providing at least partialengagement of the support beam, the arrangement being such that when thehooks having the rectangular jaw shape bear against the support beam, orshortly after a bending of these hooks, the transverse rods abut againsteach other.

By the adoption of this design of the wire grid mat sections inparticular of the ends thereof which are to be connected together, thereis achieved a coupling effect between both of the types of hooks in usewith the transverse rods, whose welded joints are shearing stress, saidtwo types of hooks being those having the rectangulanshaped jaws and theacute angled shaped jaws. At the same time, the result is achieved thata certain yieldability of the mat is retained, such yieldability beingafforded on the one hand by the clearance inherent in the matconstruction and on the other hand by a reduction in the spacingdistance of the ends of the longitudinal rods from each other.

Moreover the mat sections retain the already mentioned advantage in matconstruction of being proof against disturbance while having acomparatively low production cost and without making the manipulation ofthe mats more difficult.

Apart from this the result is achieved that each longitudinal rod isfully utilized, that is to say it can be subjected to stress up to thelimit of its parting strength.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of twosuccessive wire mesh mat sections after they have been arranged upon thesupport beams;

FIG. 1A is a side elevation of the structure shown in FIG. 1;

FIG. 2 is a plan view on a larger scale of the condition existing inFIG. 1 at one of the support beams with which are engaged two succeedingwire mesh mat sections;

FIG. 2A is a side elevation of the structure shown on FIG. 2;

FIG. 3 is a plan view showing the structure corresponding to FIG. 2, butat the end ofa first stressing phase;

FIG. 3A isa side elevation of the structure shown on FIG. 3;

FIG. 4 is a plan view showing the structure corresponding to that ofFIG. 3 but in a second phase of the stressing, which may be followedfinally by the destruction of the joint between the mat sections; and

FIG. 4A is a side elevation of the structure shown on FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the figures of the drawingcorresponding parts are indicated by the same reference characters.

For the purpose of lining a succession of support beams l, 2 of aroadway in a mine working, a number of similarly designed wire mesh matsections 3 are employed, which are connected to the support beams andare connected together at their ends in the manner to be describedhereinafter.

Each of these wire mesh mat sections comprises longitudinal rods 4 andtransverse rods 5. The longitudinal rods and transverse rods are weldedtogether at their intersection points, of which one is indicated at 6.

The ends of the longitudinal rods 40, 4b are assembled together in pairsproceeding across the width of the mat.

At one end of a mat section, namely the left-hand end in FIG. I, theassembly of the ends of a pair of longitudinal rods consists of a bentportion 7a and 7b, these ends being directed towards each other so thatthe end portions of the longitudinal rods are closer together than arethe central parts of the rods.

Moreover, at the left-hand end of the mat section the longitudinal rodsare connected together by crossbars 8, these crossbars 8 being welded tothe rods. At this end the longitudinal rods 4a, 4b are provided withhooks 9 having substantially rectangular jaw openings 10.

At the opposite end the longitudinal rods are likewise provided withbent portions lla, llllb which are again turned towards each other.However, as contrasted with the bent portions 70 and 7b the distancebetween the bent ends of the longitudinal rods is greater, so that theends of the rods carrying the crossbars 8 can be introduced between theends having the bent portions 11a, 11b.

The longitudinal rod ends 4c shown at the right-hand side of FIG. 1 areprovided with a continuous crossbar l2 welded to said ends, in contrastto the arrangement of the longitudinal rod ends 4d at the left-hand endof the mat section.

Furthermore, the ends 4c of the longitudinal rods 4a and 4b are providedwith acute angled hook jaws 14 in such a mariner that these hooks can atleast partially embrace the support beams.

In the practical example selected for description the support beams havea I profile, of which the flange 2a (FIG. 2) of the l profile beam issituated nearest to the wall face, such flange being partially embracedin the above-described manner.

As may be seen from FIG. 1 the spacing interval of the lowest pointbetween the hook jaws l and 14 is greater than the distance between thebearing edges (2b and 2e on the support beam (FIG. 2).

In accordance with this arrangement, after setting up a support framewith the support beam 2, first of all the end 4d of one mat section canbe hooked into the end 40 of the preceding mat section in such a mannerthat the short crossbars 8 and the hooked portions 4d support themselvesupon the hooks in the part 40 and upon the cross bars 12. In this wayalso the mat provides itself with forward support. In this arrangementthe mat must be retracted by an amount equal to the difference of thespacing between the deepest points of the hook jaws and the spacebetween the appertaining edges of the support beam, so that as a resultthe acute angled hook portion 14 is brought into engagement with thesupport beam. As shown, the crossbars 8 are spaced from the appertainingcrossbar 12 by a predetermined distance, which is indicated at the topof Fig. 2 by the reference a.

Upon applying stress to the longitudinal rods of the mat the distance ais progressively decreased until it is reduced to the value b (FIG. 3A).In that condition the acute angled hook jaws l4 and the right angledhook jaws l0 bear against the appertaining edges 2b, 2c of the supportbar 2. Up to this time the initial yieldability of the mat connectionhas been utilized.

If now further stress if applied to'the longitudinal rods of the matsections then the hooks l0 and 14 are placed under stress. In this waythe clearance b is put to use in such a manner that the short crossbars8 bear against the adjacent surface of the continuous cross bar 12. Thiscondition is shown in FIGS. 4 and 4A.

Thus, it is possible to design the arrangement in such a manner thatonly after the right angled hook jaw 10 comes to bear against theappertaining edge 2c of the support profile 2 is the clearance b fullyutilized. This possibility has been assumed in the practical exampleaccording to FIGS. 4 and 4A. Thus, the rectangular hook jaw 10 hasalready begun to bend outwardly. There now comes into effect the jointaction of the hook jaws l0 and [4 at the same time as the stressing ofthe welded joints of the crossbars 8 and 12.

By way of modification from the practical embodiment described, thearrangement may be so devised that the clearance b has already beenexhausted before the hook l0 begins to bend upwardly.

What I claim is:

1. A wire mesh mat for the lining of support beams in mine roadways andtunnel constructions comprising a plurality of sections joined in anend-to-end relationship wherein each section comprises longitudinal rodsand transverse rods welded together at their intersection points, thelongitudinal rods having hooks at their ends and being assembledtogether in pairs with cross bars at both ends of the section, the pairsof longitudinal rods having different spacings at opposite ends of saidrods in order to allow one section to be interengaged in sequence withanother section, longitudinal rods of the section being formed at eachend with hooks, the hooks at one end being bent at an acute angle orotherwise formed for the purpose of at least partially embracing asupport beam, and the crossbars being so arranged that when t e hooks atthe end opposite to the said one end bear against the support beam, orshortly after such hooks are subjected to bending strain, the adjacentcross bars of two interengaged sections bear against each other.

2. A wire mesh mat as claimed in claim 1 wherein the hooks at the saidopposite end are bent at substantially a right angle.

1. A wire mesh mat for the lining of support beams in mine roadways andtunnel constructions comprising a plurality of sections joined in anend-to-end relationship wherein each section comprises longitudinal rodsand transverse rods welded together at their intersection points, thelongitudinal rods having hooks at their ends and being assembledtogether in pairs with cross bars at both ends of the section, the pairsof longitudinal rods having different spacings at opposite ends of saidrods in order to allow one section to be interengaged in sequence withanother section, longitudinal rods of the section being formed at eachend with hooks, the hooks at one end being bent at an acute angle orotherwise formed for the purpose of at least partially embracing asupport beam, and the crossbars being so arranged that when the hooks atthe end opposite to the said one end bear against the support beam, orshortly after such hooks are subjected to bending strain, the adjacentcross bars of two interengaged sections bear against each other.
 2. Awire mesh mat as claimed in claim 1 wherein the hooks at the saidopposite end are bent at substantially a right angle.